EWA strives to be a “good neighbor” by implementing measures to minimize the discharge of air emissions and odors from the treatment plant. Activities include: routine maintenance and testing of the cogeneration engines to ensure compliance with emission standards; tracking and annual reporting of greenhouse gas (GHG) emissions for the facility; and daily checks of odor reduction facilities to ensure effective operation. Additional air quality controls include the following:
- Both primary sedimentation tanks and secondary aeration basins are covered. While covering the primaries is common practice, very few treatment plants cover the secondary basins.
- Liquid and solids treatment processes are vented through a biological scrubber and/or carbon. In accordance with EWA’s air permits, the carbon is tested annually and replaced when the sulfur content exceeds required compliance standards.
- While loading biosolids into trucks, building doors are kept closed.
- Before putting a primary sedimentation tank or secondary clarifier online, the tanks are pre-filled with recycled water to minimize odor production.
EWA typically gets very few odor complaints. When one is received, a formal procedure is followed including: documenting the complaint; conducting an investigation; taking action to mitigate the source of the odor if it originates from the EWPCF; and following up with the complainant regarding the results of the investigation and any actions taken.